Water pressure calculator



Oct. 30, 1934- M, R. CRANE ET AL WATER PRESSURE CALCULATOR Filed July 18, 1952 2 Sheets-Sheet l EN 1m Oct. 30, 1934. M. R. CRANE ET AL 1,978,402

WATER PRES SURE CALCULATOR Filed July 18. 1932 2 Sheets-Sheefl 2 Inventor:

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Patented Oct. 30, 1934 PATENT orries WATER PRESSURE CALCULATOR Mathias R. Crane and Ernest F. Coop, Pasadena, Calif.

Application July 18, 1932, Serial No. 623,274

1 Claim.

This invention relates to a novel calculator which is especially designed to expedite calculation of water pressure intended to be delivered through a fire hose.

a More explicitly stated, the invention has referpractical and expedient accessory of this class which may be conveniently utilized to enable the attendant or engineer of the engine. to determine the requisite pressure for various layouts of hose and different sized nozzles for said hose.

Briefly described, the preferred embodiment of i the invention comprises an appropriate casing for the mechanism having an apertured face plate I with suitable indicia thereon, a transparent calculating and indicating dialmounted for rota- .tion in the casing, and operating means therefor, together with illumination means in the casing to permit the numerals on the dial to be readily observed.

Referring now to the drawings:

Figure 1 is a front elevation of a device constructed in accordance with the principles of the present invention.

Figure 2 is a view in section and elevation disclosing the details more clearly.

Figure 3 is an elevational view of the partitioning and supporting plate.

Figure 4 is a view somewhat similar to Figure 2 showing the essential features in section.

Figure 5 is a fragmentary view of the dial.

Referring now to the drawings by distinguishing reference characters, it will be observed that the casing proper, which is preferably of copper, is denoted by the numeral 5 and secured to the open side thereof through the medium of attaching 0 .bolts 6 is a disc-like face plate 7 which as shown in Figure 1 is provided with a segmental shaped opening 8 constituting a sight.

Printed or otherwise displayed on the plate opposite the sight and along one edge thereof are requisite figures and numerals for indicating the "sizes of the hose and tips and at the opposite side of the opening is a row of letters, the first letters in the row F. T. meaning feet and all the other letters E. P. meaning engine pressure. :Mounted in the interior of the casing is a partition plate 9 secured in place by retaining bolts 10 and spacing sleeves l1. This plate as seen in Figure 3 is provided with asegmental opening 12 in registry with the sight opening 8. i

A suitable bracket or fixture 13 is employed for attaching a socket 14 and bulb 15 to the plate so that the rays of light from the bulb are allowed to project through the openings 12 and 8 respectively.

The numeral 16 designates a transparent rotary dial having circumferential rows of radially spaced calibrations or numbers properly graduated for registration with the sight opening 8 and co-operable with the indicia on the face plate to permit the different pressures to be readily ascertained. Each row of numbers on the dial has the first numerals in the row indicating feet and this number will be opposite the abbreviation F. T. when the row is appearing through the opening. The other numerals in each row 7 indicate engine pressure. For instance, with the row of numerals on the dial arranged at the window, as shown in Figure 1, said. numerals will indicate that 100 feet of 2 inch hose will require an engine pressure of 62 pounds when a 7 1 inch tip is used on the hose, 69 pounds when a 1 inch tip is used on the hose and 78 pounds when a 1% inch tip is used on the hose. The next row of numerals on the dial will indicate engine pressure required for a different length of hose, as shown in Figure 5.

At its center, this dial is attached to a rotary tubular shaft 17 which as seen in Figure 4 is provided with a suitable operating knob 18. The numeral 19 designates a conventional one-throw 8 switch to which the solid shaft 20 is connected. The shaft 20 extends through the tubular shaft and through an appropriate bearing carried by the plate 9, and said shaft is provided on its outer end with an operating knob 21. Thus the switch is controlled by the knob and shaft 20.

The switch is connected by a suitable conductor 22 to the incandescent lamp and connected by a complemental conductor 23 to a binding post 24 carried by the plate 9. Current is supplied to the 1;, lamp through these conductors and the switch by way of a. conventional storage battery with which the pumping engine is usually equipped.

As before explained, the calculating device is intended to be attached to a conventional fire pumping engine and manually operated to accu- .rately indicate to the engineer the engine presderstanding of the invention to be had. Therefore a more lengthy description is thought unnecessary. While the preferred embodiment of shaft passing through the hollow shaft and' the knob, a second knob connected to the outer end of the second shaft and located in front of the first knob, the inner end of the second shaft extending beyond the inner end of the first shaft, a bearing in the casing for said extended end of the second shaft and a switch for the lamp circuit connected with the inner end of the second shaft.

MATHIAS R. CRANE. ERNEST F. COOP. 

